The invention relates generally to the field of photography, and in particular to the manipulation of multiple images in an electronic imaging system. More specifically, the invention relates to a compositing technique for inserting a subject into a different background.
Known digital imaging systems allow a user to extract people or objects from a scene, and composite them in front of a different, xe2x80x9cfunxe2x80x9d background, such as a Las Vegas skyline or an image of the moon. In the past, two methods have been used to accomplish this result: (1) A special uniformly colored screen or bright background is used behind the people/objects of interest, and a foreground mask is created using a xe2x80x9clinear blue screenxe2x80x9d method or xe2x80x9cchroma keyxe2x80x9d method. An example of this method is described in U.S. Pat. No. 5,424,781. This method can give excellent results, but requires that the user have an expensive, carefully lit, colored background. (2) The people/objects of interest may be captured in front of any type of background, and then xe2x80x9ccutyxe2x80x9d out of the background electronically using software tools available in such software packages as Adobe Photoshop(trademark) version 3.0, for example. Unfortunately, for most subjects such as people, use of such software tools is a time-consuming and difficult process that typically yields a less than realistic looking border around the image.
What is required is a method of extracting people/objects of interest that can quickly and easily be accomplished by inexperienced users, and hat gives acceptable results, without requiring a special colored background.
The present invention is directed to overcoming one or more of the problems set forth above. Briefly summarized, according to one aspect of the present invention, an electronic imaging system useful for compositing images includes an electronic camera for capturing multiple images, including a first image of a subject plus background and a second image of the background only; means for subtracting the first and second images to generate a difference image; means for processing the difference image to generate a mask image; and means for applying the mask image to the first image to select an area in which the subject is located, whereby the selected subject area is used in the compositing of a new image.
By taking a first picture of people and/or objects in front of any type of background (rather than using a specially colored background), followed by a second picture after the people/objects are removed, a system is obtained which provides quick and easy results, even by inexperienced users. The second image is subtracted from the first, and the result is automatically processed in order to create a foreground xe2x80x9cmaskxe2x80x9d that is used to extract just the people/objects, can then be composited into any desired background.
These and other aspects, objects, features and advantages of the present invention will be more clearly understood and appreciated from a review of the following detailed description of the preferred embodiments and appended claims, and by reference to the accompanying drawings.